1. Field of the Invention
The present invention relates to a method and an apparatus for joining, to a protective tape joined to a surface of a semiconductor wafer, a separation tape having a width narrower than a diameter of the semiconductor wafer to separate the protective tape together with the separation tape from the surface of the semiconductor wafer.
2. Description of the Related Art
Conventionally, a chip component has been manufactured from a semiconductor wafer (hereinafter, appropriately referred to as a “wafer”) in accordance with the following procedure.
As disclosed in JP2002-124494A, for example, a circuit pattern is formed on a surface of a wafer, and then a protective tape is joined to the surface of the wafer. Thereafter, a back grinding process is performed on a rear face of the wafer in order to thin the wafer. The thinned wafer is held by a ring frame through a dicing tape. In this state, the protective tape is separated from the surface of the wafer. Thereafter, a dicing process is performed on the wafer.
In the case where the protective tape is separated from the thinned wafer, the wafer is frequently damaged from a stress to be applied thereto when the protective tape is joined thereto or separated therefrom, because of reduction in strength. In the back grinding process, particularly, such a stress causes further growth of a defect such as a chip or a crack on an outer periphery of the wafer, resulting in increase of the damage. If the wafer is further damaged by the growth of the defect and, consequently, the protective tape can not be separated from the wafer because of the damage, the wafer is discarded before being subjected to the dicing process.
For this reason, all the chip components including usable non-defectives are discarded, so that there arises a problem of reduction in yield.